Synthesis, Characterization, and Photocatalytic Properties of Flower-like Mn-doped Ceria

Abstract

Mn-doped CeO 2 flower-like microstructures have been synthesized by a facile one-step compositehydroxide-mediated method. The structure, morphology, optical and the surface properties of Mn doped CeO 2 have been investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), UV-Vis absorption spectroscopy and X-ray photoelectron spectroscopy (XPS). The XRD results confirmed the successful incorporation of Mn into the CeO 2 lattice through the formation of face-centered cubic solid solution. The photocatalytic activities of the catalysts were evaluated by measuring the photodegradation efficiency of Rhodamine B (RhB) under ultraviolet light irradiation. With an optimal molar ratio of 1% in Mn/CeO 2 the highest rate photodegradation was achieved under the experimental conditions. The enhanced photocatalytic activity can be attributed to the incorporation of multivalent Mn in CeO 2 promoted the separation of photogenerated charges, inhibited the recombination of photogenerated carriers, and thus prolonged the charges lifetime to participate in the photocatalytic reaction.

Ethanol Steam Reforming on CexMyO2 (M: Cu, Zn, and Mn) Solid Solution Catalysts

“…3 presents XRD patterns of the prepared samples before (a) and after reaction (b). Mn-, Cu-, and Zn-doped CeO 2 samples had peaks in approximately the same position corresponding to (111), (200), (220), (311), (222), and (400) planes according to the XRD patterns, being in agreement with Joint Committee on Powder Diffraction Standards (JCPDS) cards [28][29][30] report by Takalkar [31] for the crystallite size of CeCu, CeZn, and CeMn in the order of CeCu > CeMn > CeZn. XRD patters of samples after ESR (Fig.…”

“…3 presents XRD patterns of the prepared samples before (a) and after reaction (b). Mn-, Cu-, and Zn-doped CeO 2 samples had peaks in approximately the same position corresponding to (111), ( 200), ( 220), (311), (222), and (400) planes according to the XRD patterns, being in agreement with Joint Committee on Powder Diffraction Standards (JCPDS) cards [28][29][30]. Differences in intensity or a little position shift com-pared to CeO 2 indicated the formation of Mn-, Cu-, and Zn-doped CeO 2 and peaks related to CuO, ZnO, and Mn x O y could be justified by more dopant from the CeO 2 lattice, so remaining on the surface was detected.…”

Enhanced photocatalytic reduction of 4‐nitrophenol over Ir/CeO2 photocatalysts under UV irradiation

“…Notwithstanding this, some authors have reported that CeO 2 presents a disadvantage related to the rapid recombination of the charge carriers (e − − h + ) formed in the process, which limit its applications in photocatalytic processes. 29,30 In order to reverse this disadvantage, modifications of the semiconductor by addition of transition metals 25,31 and metallic oxides 32 have successfully enhanced the physicochemical properties and increase the photoactivity of the material. This modification with transition metals by doping might induce crystalline defects and favor charge transference towards adsorbed species increasing photocatalytic activity.…”

Synthesis of Ce-La-Pr/Mn-O Ternary Oxide Composites via Co-Precipitation and Synergistic Photocatalytic Degradation of Cr(VI)

“…For direct band gap semiconductors, the exponent n equals 1/2, whereas for indirect band-gap semiconductors, it equals 2. Given that Ce-La-based composites exhibit indirect band-gap characteristics [31], an exponent of n = 2 was employed in our analysis. Based on these calculations, the band gaps of Ce-La, Ce-La-Pr, and Ce-La-Mn are 2.30 eV, 2.01 eV, and 1.91 eV, respectively.…”